The invention relates to surgical knives for percutaneous use.
The desire to perform procedures least invasively, i.e., with a minimum degree of opening the body, has led to percutaneous surgery in which the surgical knife is manipulated through a puncture opening, under visual guidance of an endoscope. Arthroscopic surgery of the knee is a common example of such surgery. Typically, the knife is introduced through a cannula to avoid unwanted cutting during introduction of the blade through the flesh. In some instances, the surgeon removes the cannula after the knife is introduced; in others, the cannula is left in place. An example of the latter is Oretorp, U.S. Pat. No. 4,444,184, a surgical instrument which combines an elongated tube and a blade which is projected axially out of the tube after introduction of the instrument through the flesh.